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Exercise 13 ? 2007 Rockwell Automation, Inc. All rights reserved. Rev. 071110 Performance Equations What You Will Learn How to use Performance Equations to perform server-side recordable instance and summary calculations. As we saw in the previous exercise, the calculations available in Data Sets can be very useful. The do however have two major limitations in that they cannot be easily shared and it is not possible to record the results in the archive. Performance Equations solve both these limitations by moving the execution of the calculations to the server. 1. Verify that you are on the VM-HIST image by checking the hostname on the background image: 2. Launch the System Management Tools (SMT). 3. Expand the “Points” category and select the “Performance Equations” plug-in: 4. Our first performance equation is going to be a Fahrenheit to Celsius conversion. Click on the “New” toolbar button to begin creation of a new Performance Equation tag: Page 2 Ex13 – Performance Equations Rev. 071110 ? 2007 Rockwell Automation, Inc. All rights reserved. 5. On the “General” tab, set the following fields: o Name: T100_Demo_Temp_DegC o Descriptor: Tank T100 Temperature o Point type: Float32 o Eng Units: Deg C 6. On the “Equation” tab, set the “Equation” to: (‘CDT158’ -32) * 5/9 Click the “Evaluate” button just to make sure you don’t get an error. Actual value will differ: 7. On the “Scheduling” tab, change the radio button to “Event-based scheduling”. Change the timestamp assignment option to “timestamp of the triggering event”. Use the “…” button (not pictured) to select the tag: CDT158 Ex13 – Performance Equations Page 3 ? 2007 Rockwell Automation, Inc. All rights reserved. Rev. 071110 8. On the “Archive” tab, set the following fields: o Exception Deviation: 0.25 o Compression Deviation: 0.5 o Compression Max Time: 15 Min 9. Click the “Save” toolbar button and check fo